Homebrew PCBs

what is sulfate of zinc and acidulated water and saturated copper 
sulfate crystals ?
Do we have any chemists out there?

I found an old time article how to make a battery and it specified

  sulfate of zinc and acidulated water and saturated copper sulfate crystals

http://www.learnmorsecode.com/regen2/battery02.jpg

The article said to use ZINC SULFATE
or
ACIDULATED water.

So I got look up ZINC SULFATE on the web and is says we can buy 220mg 
zinc sulfate capsules...to eat.
huh?!!??
edible batteries?

Zinc Sulfate (220mg) - 100 Capsules
Zinc sulfate is an inorganic compound and dietary supplement. As a 
supplement it is used to treat zinc deficiency


but hey...it did say "OR"
and when I look up acidulated water it said

wiki:
Acidulated water is water that an acid has been added to it, usually 
lemon juice, lime juice or vinegar. Citric acid and ascorbic acid can 
also be used.

  Acidulated water can be made by combining 1.5 tablespoons vinegar or 3 
tablespoons lemon juice.

sooooo...... OK... this doesn't sound real toxic or dangerous to show 
and tell kids battery chemistry....

AND THEN
there is the saturated copper sulfate....
which is readily available at th eharware store
  ROOT KILL copper sulfate pentahydrate 99%
and instructions on the web say:

First, you need a saturated copper sulfate solution so the crystals can 
form as the liquid evaporates. All you need to do to make the solution 
is to stir copper sulfate into very hot water until no more will 
dissolve. There are two ways to grow the crystals.Apr 26, 2014
How To Grow Blue Copper Sulfate Crystals - Science Notes and Projects
https://sciencenotes.org/how-to-grow-blue-copper-sulfate-crystals/

OR
just buy 10 pounds of crystals from a seed supply house for $32.

So is this feasible or would parents be pissed if they knew their kids 
were near these chemicals?